高效液相色谱串联质谱法测定中药注射剂对P815细胞脱颗粒后上清液中组胺含量

建立了液相色谱-串联质谱(LC-MS/MS)检测P815细胞脱颗粒后上清液中组胺含量的方法。采用C18柱(4.6 mm×100 mm,3.5μm)进行分离,以体积比为60∶40的乙腈-0.5 mmol/L乙酸铵溶液(含0.3%甲酸)为流动相,流速0.4 mL/min;在电喷雾正离子化模式下,采用多离子反应检测方式(MRM)进行检测;检测离子对为m/z 112>95、112>68。在优化条件下,样品可在6 min内完成分析,细胞液中组胺在4.0～128.0μg/L范围内线性关系良好(r2=0.997 9)。定量下限(S/N>10)为1.2μg/L,检出限(S/N=3)为0.3μg/L。在加标水平为16、64、128μg/L时,细胞上清液中组胺的平均回收率为90%～94%,相对标准偏差(n=6)为4.1%～5.9%。该方法简便、灵敏、重复性好,可用于中药注射剂对P815细胞脱颗粒后上清液中组胺含量的测定。     

高效液相-荧光检测法快速测定血清中的色氨酸

 利用色氨酸具有自然荧光的特点 ,建立了测定血清中色氨酸浓度的高效液相 荧光检测分析方法。血清标本经高氯酸沉淀蛋白后取上清液进行分析 ,柱为Nova PakC18柱 ,流动相为 5mmol/L磷酸二氢钾水溶液 ,流速为 1mL/min ,激发波长为 2 5 4nm ,荧光检测波长为 338nm。该法检测色氨酸浓度的线性范围为 0 4 9μmol/L～ 4 90 0 0 μmol/L ,最低检测限为 0 10 μmol/L ,回收率为 97 2 %～ 98 6 % (平均值为 97 9% ) ,批内、批间相对标准偏差均小于 5 % ,苯丙氨酸、酪氨酸、5 羟色胺和 5 羟吲哚乙酸等物质对该法均无干扰。     

胶束扫集毛细管电泳快速测定止咳露中的麻黄碱和可待因

采用胶束扫集毛细管电泳, 建立了快速测定止咳露中麻黄碱和可待因含量的方法, 并通过日间实验、柱间实验等对方法的稳定性进行了考察研究.胶束扫集电动色谱缓冲体系含60 mmol/L 十二烷基磺酸钠, 10 mmol/L NaH2PO4 (pH 2.20), 18%乙腈(V/V), 分离电压-14 kV, 测量波长200 nm. 讨论了pH、 SDS浓度、样品溶剂等对分离效果的影响. 在优化条件下, 麻黄碱和可待因均在5 min内出峰, 方法检出限(μg/mL)、线性范围(μg/mL)、相关系数分别为: 麻黄碱 0.433、 1.73～27.7、 0.9997, 可待因0.833、 3.33～50.3、 0.9996, 回收率在96.7%～103.5%之间. 峰面积日内RSD≤4.2% (n=5), 日间RSD≤8.0% (n=5), 柱间实验RSD≤2.3% (n=3).     

高效液相色谱-串联质谱法测定犬血浆中雌三醇的含量

取犬血浆500μL,加入20.0μg·L~(-1)氯霉素内标甲醇溶液50μL,用甲基叔丁基醚(MTBE)先后萃取2次,使样品中雌三醇(E_3)溶入MTBE中,MTBE的加入量均为1.00mL,充分摇匀2.0min后,离心10min。收集并合并2次萃取的上清液,氮吹至干。加入甲醇100μL溶解残渣后再次离心10min,取上清液(10.0μL)进样进行色谱分离。用Agilent XDB-C18色谱柱为固定相,和以不同比例的乙腈(A)和水(B)的混合液作流动相进行梯度洗脱。串联质谱分析中采用电喷雾离子源负离子扫描和多反应监测模式。测得E_3的线性范围在0.2～40.0μg·L~(-1)之间,测定下限(10S/N)为0.2μg·L~(-1)。在空白犬血浆中加入E_3标准溶液进行回收率和精密度试验,测得日间回收率在93.3%～110%之间,测定值的日内和日间相对标准偏差(n=5)分别在1.6%～3.1%和4.2%～5.9%之间。     

沙棘黄酮口服液中芦丁和5-羟色胺的毛细管区带电泳电化学检测

建立了毛细管区带电泳 -电化学检测法 (CE -ED)测定芦丁和5_羟色胺含量的方法 ,研究了电极电位、运行缓冲液的酸度和浓度、电泳电压及进样时间等因素对分离检测的影响,确定了最佳测定条件 ;以直径为300μm的碳圆盘电极为检测电极,电极电位为0.90V(vsSCE),在50mmol/L硼酸盐缓冲液(pH8.5)中,上述2组分在12min内完全分离 ,被分析物的电流响应与浓度在约3个数量级范围内呈良好线性关系,检出限分别为3×10-7 mol/L和8×10-8 mol/L ,7次测定含5.0×10-4 mol/L的芦丁和5_羟色胺的标准溶液,峰高的相对标准偏差分别为2.5 %和3.8 % ;该法成功地用于中药沙棘黄酮口服液中芦丁和5_羟色胺的测定     

高效液相色谱法测定血浆中左亚叶酸钙的含量

建立了测定血浆中左亚叶酸钙含量的RPHPLC方法。采用DiamonsilC18色谱柱(150mm×4.6mm,5μm),乙腈50mmol/L磷酸氢二钾/磷酸二氢钾缓冲溶液(10∶90,V/V,用磷酸调pH至4.0)为流动相,用前经0.45μm的过滤膜,超声脱气,流速为1.0mL/min,紫外检测波长为290nm,柱温为35℃,进样量20μL。该方法最低检出限为0.2ng;线性范围为0.05～10mg/L,方法平均回收率在97.0%以上;日内及日间精密度的相对标准偏差分别小于4%和6%。该方法简单,快速,灵敏度高,重复性好。     

鼠脑组织中6-羟基-1-甲基-1,2,3,4-四氢-β-咔啉及其相关生物胺的高效液相色谱-电化学检测

建立了大鼠脑组织中6-羟基-1-甲基-1,2,3,4-四氢-β-咔啉(6-OH-MTHβC)、5-羟色胺(5-HT)和5-羟吲哚乙酸(5-HIAA)含量的高效液相色谱-库仑阵列电化学检测(HPLC-ECD)方法。采用的色谱柱为DiscoveryHS F5柱(250 mm×4.6 mm,5 μm),流动相为缓冲液（40 mmol/L柠檬酸+20 mmol/L磷酸氢二钠+0.3 mmol/L乙二胺四乙酸二钠,pH 4.0）-甲醇（体积比为78∶22）混合液,流速为1 mL/min。6-OH-MTHβC、5-HT、5-HIAA在1.0～500.0 μg/L范围内线性关系良好(r>0.9992),检出限分别为0.56,0.26,0.53 μg/L,日内和日间精密度(以相对标准偏差表示)均低于6.1%,回收率分别为87.1%～98.2%,87.0%～95.3%,90.1%～97.7%。用该方法检测新生7 d的SD胎鼠脑内6-OH-MTHβC及5-HT、5-HIAA的含量,发现SD胎鼠在急性酒精中毒8 h后6-OH-MTHβC显著上升(P<0.05);而5-HT和5-HIAA的含量有所下降,但无显著性差异。该法简便、稳定、灵敏度高,适用于测定鼠脑组织中6-OH-MTHβC和5-HT,5-HIAA含量的相关研究。     

柱前衍生法测定烟叶中的7种生物胺

建立了丹磺酰氯柱前衍生高效液相色谱法(HPLC)测定烟草基因编辑素材中的7种生物胺的方法。采用0.4 mol/L HClO_4进行样品超声提取,提取液经过pH调整后,利用丹磺酰氯(4 mg/mL)进行柱前衍生;衍生后的样品溶液利用优化的HPLC-DAD色谱方法进行检测;方法在1.0～50μg/mL范围内具有较好的线性(R~2 0.98),检出限在0.01～0.15μg/mL之间,定量限在0.05～0.25μg/mL之间,日间和日内精密度均小于5%,不同加标水平下,平均回收率在86.7%～124.0%之间。     

超高效液相色谱串联质谱法测定尿液和血液中15种芬太尼类新精神活性物质的含量北大核心CSCD

在尿液或血液样品1.0 mL中加入100μg·L芬太尼-d内标溶液100μL和0.1 mol·L^(-1)盐酸溶液4 mL,振荡,离心。上清液过已活化的MCX固相萃取柱,将洗脱液氮吹至近干,残渣用体积比9∶1的含0.1%(体积分数)甲酸的5 mmol·L^(-1)乙酸铵缓冲溶液-乙腈混合液溶解,并定容至1 mL,经0.22μm有机滤膜过滤,采用超高效液相色谱串联质谱法(UHPLC-MS/MS)测定其中15种芬太尼类新精神活性物质的含量。以ACQUITY UPLC BEH C色谱柱为固定相,以不同体积比的含0.1%甲酸的5 mmol·L^(-1)乙酸铵缓冲溶液-乙腈混合液为流动相进行梯度洗脱。质谱分析中采用电喷雾离子源正离子(ESI~+)模式和多反应监测(MRM)模式。结果表明,15种芬太尼类新精神活性物质标准曲线的线性范围均为0.5~50.0μg·L^(-1),检出限(3S/N)均为0.1μg·L^(-1)。对空白样品进行加标回收试验和日内(n=6)、日间(n=6)精密度试验,回收率为81.1%~113%,测定值的相对标准偏差均小于15%。     

高效液相色谱法测定畜禽肉中8种生物胺含量国家标准方法的改进北大核心CSCD

针对国家标准方法GB 5009.208-2016操作繁琐,检测时间较长(约6 h)等问题,改进了提取方法和衍生方法,并应用于畜禽肉中色胺、尸胺、β-苯乙胺、酪胺、亚精胺、腐胺、组胺和精胺等8种生物胺含量的测定。取绞碎样品10 g,加入50 g·L^(-1)三氯乙酸溶液20 mL、正己烷10 mL及1 000 mg·L^(-1) 1,7-二氨基庚烷内标溶液1.0 mL,混匀后涡旋15 min,超声提取15 min,离心5 min。取0.5 mL上清液置于10 mL比色管中,依次加入2 mol·L^(-1)氢氧化钠溶液100μL、饱和碳酸氢钠溶液300μL、10 g·L^(-1)丹磺酰氯衍生溶液2.0 mL,振荡混匀,于60℃反应15 min。加入100μL氨水,于60℃保温15 min,以终止衍生反应。加入乙腈稀释至5 mL,用0.22μm滤膜过滤,滤液注入高效液相色谱仪,在Phenomenex Kinetex色谱柱上以不同体积比的甲醇-水体系进行梯度洗脱,并用二极管阵列检测器检测。结果显示:样品可在1.5 h内完成检测,8种生物胺的质量浓度均在5.00~250 mg·L^(-1)内与其对应的峰面积与内标物峰面积的比值呈线性关系,检出限(3S/N)为4~21μg·kg^(-1);对实际样品进行加标回收试验和日内、日间精密度试验,回收率为80.4%~95.6%,日内(n=6)、日间(n=5)精密度试验测定值的相对标准偏差分别为1.9%~5.1%和2.3%~6.2%;方法用于20批畜禽肉的分析,除组胺外,其他7种生物胺均有不同程度检出。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.